Category 4 Earl headed for a close brush with North Carolina

Powerful Category 4 Hurricane Earl is pulling away from Puerto Rico and the northern Lesser Antilles Islands, and is eyeing its next potential landfall--North Carolina's Outer Banks. Earl brought heavy rain and high winds to Puerto Rico and much of the northern Lesser Antilles yesterday, though it appears that the islands were spared major damage. One exception may be Anegada in the British Virgin Islands, population 200. The eye of Earl passed just north of Anegada at noon yesterday, and Earl's south eyewall probably brought sustained winds of 100 mph to the island. Second hardest hit was probably Anguilla. Amateur weather observer Steve Donahue at anguilla-weather.com estimated gusts of 100 mph on Anguilla; his anemometer broke at 88 mph. Winds in St. Thomas in the U.S. Virgin Islands remained above tropical storm force (39 mph) for five hours yesterday afternoon, peaking at 52 mph, gusting to 62 mph, at 4:49 pm. Heavy rains hit Puerto Rico, where radar-estimated rainfall amounts of up to 5 - 7" occurred. Earl brought waves of sixteen feet to San Juan, and waves at buoy 41043 offshore of Puerto Rico reached 31 feet early this morning.

Figure 2. Radar estimated rainfall for Earl from the San Juan, Puerto Rico radar. Isolated regions of 5 - 7 " of rain occurred in three locations on Puerto Rico. The rays fanning out to east from the radar location marked with a "+" are due to mountains blocking the view of the radar.

Intensity forecast for EarlWind shear as diagnosed by the latest SHIPS model forecast shows a moderate 10 - 20 knots of wind shear over Earl, due to upper level winds out of the southwest from a trough of low pressure to Earl's west. This moderate shear is predicted to continue through Friday, but should not appreciably affect Earl, since the hurricane is so large and strong. Ocean temperatures are a near-record 29.5 - 30°C, and very warm waters extend to great depth, resulting in a total ocean heat content favorable for intensification. Earl is undergoing an eyewall replacement cycle, which may diminish its winds by 10 -20 mph for a day or so. However, the storm will probably regain strength after completing this cycle, and it is likely Earl will be a major Category 3 or 4 hurricane at its closest approach to North Carolina Thursday night and Friday morning. By Friday night, when Earl will be making its closest approach to New England, wind shear will rise to a high 20 - 30 knots and ocean temperatures will plunge to 20°C, resulting in considerable weakening. Earl will still probably be a Category 2 hurricane on Friday night, when it could potentially make landfall in Massachusetts. Earl is more likely to be a Category 1 hurricane on Saturday morning, when it could potentially make landfall in Maine or Nova Scotia, Canada.

Track forecast for EarlThe latest set of computer models runs from 2am EDT (6Z) this morning push Earl's projected track a little closer to the U.S. East Coast, and we now have two of our six reliable models predicting a U.S. landfall. The latest NOGAPS run shows Earl hitting the Outer Banks of North Carolina late Thursday night, then striking Southeast Massachusetts late Friday night, and Eastern Maine on Saturday morning. The HWRF model predicts a strike on Eastern Maine Saturday morning, but keeps Earl offshore from North Carolina and Massachusetts. None of the other computer models show Earl hitting the U.S., but several models bring Earl within 100 - 200 miles of North Carolina's Outer Banks and Southeast Massachusetts. It is likely that Earl will being a 12-hour period of heavy rain and tropical storm force winds of 39+ mph to North Carolina's Outer Banks, beginning on Thursday evening. NHC is giving Cape Hatteras a 12% chance of receiving hurricane force winds. By Friday evening, western Long Island, Rhode Island, and Southeast Massachusetts can expect a 6 - 8 hour period of heavy rain and tropical storm force winds of 39+ mph. NHC is giving Nantucket a 11% chance of receiving hurricane force winds. These odds are 4% for Boston, 6% for Providence, 5% for Eastport, Maine, and 11% for Yarmouth, Nova Scotia. The main determinant of whether Earl hits the U.S. or not is a strong trough of low pressure predicted to move off the U.S. East Coast Friday. This trough, if it develops as predicted, should be strong enough to recurve Earl out to sea. Keep in mind that the average error in position for a 3-day NHC forecast is 185 miles, which is about how far offshore Earl is predicted to be from Cape Hatteras three days from now. The average error in a 4-day forecast is 255 miles, which is about the distance Earl is expected to be from the coast of New England four days from now.

Regardless of Earl's exact track, the U.S. East Coast can expect a long period of high waves beginning on Thursday. Significant beach erosion and dangerous rip currents will be the rule, due to waves that will reach 10 - 15 feet in offshore waters. Waves from Hurricane Danielle killed two swimmers in the U.S. over the weekend and forced hundreds of water rescues along the U.S. East Coast. Earl's waves will be worse, and will likely cause millions of dollars in beach erosion damage.

FionaTropical Storm Fiona is speeding west-northwest towards Hurricane Earl, but is unlikely to bring tropical storm force winds to the Lesser Antilles. Satellite loops show that heavy thunderstorm activity has increased in some of the outer bands this morning, but remains limited near the center. Wind shear is currently moderate, 10 - 15 knots, and the main impediment to development continues to be dry air associated with the Saharan Air Layer (SAL) surrounding the storm.

Forecast for FionaFiona is moving quickly to the west-northwest, at about 24 mph. This means it is catching up to Earl, which is moving at 15 mph. By tonight, Fiona will be beneath Earl's upper-level outflow channel. Strong upper-level winds from Earl's upper-level outflow and a ridge of high pressure to the northwest of Fiona will bring high levels of wind shear, 20 - 30 knots, to Fiona tonight through Friday, and probably arrest the storm's development. The scenario now called for by all the models is for Fiona to be drawn into the low pressure wake of Earl and turn to the northwest. Fiona will pass to the northeast of the Lesser Antilles, and will probably not bring tropical storm force winds to the islands. Fiona should then continue to the northwest and then turn north, passing very close to Bermuda on Saturday morning. It is possible Earl could destroy Fiona through high wind shear before Saturday.

Figure 4. Morning satellite image of Fiona. High level cirrus clouds flowing out from the center of Earl as part of its upper level outflow can be seen starting to impinge upon the western side of Fiona's circulation.

Danielle is deadTropical Storm Danielle has succumbed to the cold North Atlantic waters, and is no longer a tropical storm.

98LA new tropical wave (Invest 98L) moved off the coast of Africa yesterday, and is centered a few hundred miles south of the Cape Verdes Islands. Strong easterly winds from the African Monsoon are creating a moderate 10 - 20 knots of shear, and the disturbance is currently disorganized. A large area of dry air lies to the north and west of 98L, and this will interfere with development. The latest SHIPS model forecast predicts shear will remain moderate, 10 - 20 knots, for the next five days, and some slow development of 98L is possible as it moves westward at 15 mph. NHC is giving a 10% chance of this system developing into a tropical depression by Thursday, and none of the computer models develop it.

Figure 5. Morning satellite image of 98L.

A rare triple threat in the Western PacificOver in the Western Pacific, we have an unusual triple feature--three named storms all within 700 miles of each other. A 3-way interaction between these storms is occurring, making for a very tough forecast situation. The storm of most concern is Typhoon Kompasu, which hit Okinawa today as a Category 2 typhoon. Kompasu is expected to recurve northeastward and hit North Korea on Thursday as a Category 2 typhoon. It is unusual for a powerful typhoon to thread the tight Yellow Sea and hit North Korea, and I don't know how prepared they are for strong typhoons. Kompasu is expected to hit the most populous region of North Korea, but the country is pretty mountainous, and a significant storm surge disaster is probably unlikely. In the South China Sea, Tropical Storm Lionrock and Tropical Storm Namtheun are moving through the straights between Taiwan and China towards each other. Neither are predicted to develop into typhoons, but heavy rains are occurring in Guangdong and Fujian Provinces, further exacerbating the flood conditions China has suffered this summer.

Figure 6. An unusual triple feature over the Western Pacific--three simultaneous named storms all within 700 miles of each other. Image credit: NOAA/SSD.

"Hurricane Haven" airing again this afternoonTune into another airing of my live Internet radio show, "Hurricane Haven", at 4pm EDT today. Listeners will be able to call in and ask questions. The call in number is 415-983-2634, or you can post a question to broadcast@wunderground.com. Be sure to include "Hurricane Haven question" in the subject line.

there are other people that do it, nhc is not unique in that respect...however, your point is taken in the respect that many of the incorrect forecasts put out here just get dusted under the rug and nothing is said about being wrong...I'm talking even from the top bloggers, not comments

seems as though the trough is pushing against that high and flattening it out and will in lamens terms roll over the top slightly and the high will flatten more and orient more evenly which allows earl to move more wnw and westward.

StormW...my(and Dr. Masters) order of who to listen to to best be prepared to protect your life/family/property is, in order:1. NHC2. Local authorities3. Anyone else that you use as a supplement(Dr. Masters, weatherguy03, weather456(featured blogger), StormW, Levi, etc...Are you saying that in a life and death situation that you would advise people to change that order around and put yourself on top?

Quoting pipelines:I don't get why everyone tries to bash the NHC because they weren't completely accurate on their 5 day forecast "cone". You mean to tell me, that man was wrong in predicting what mother nature is doing? That never happens!

You know why it appears that the NHC has a greater rate of inaccuracy than Dr. Masters, Stormw, etc? Because they are the only ones going out on a limb putting out a visible 5 day track. Storm doesn't do this, Dr. Masters doesn't do this, you know why? Because getting it right 5 days out is HARD, very hard. The only reason the NHC does it is because it is expected of them and that is their job. Yes they are wrong a lot, and that is because humans as a race lack complete understanding of weather. If you want to blame anyone for not being able to accurately, 100% predict the weather, then blame the young age of our species and our lack of complete understanding.

there are other people that do it, nhc is not unique in that respect...however, your point is taken in the respect that many of the incorrect forecasts put out here just get dusted under the rug and nothing is said about being wrong...I'm talking even from the top bloggers, not comments

That's because a lot of people aren't used to seeing the 'wobble' of a hurricane's progress. You really need to look at several pictures to determine what direction the thing is going.

Yeah. Having radar was very helpful yesterday. I hate trying to discern motion from satellite. I almost always see a bend in the last couple of frames that is hard to ignore, even if I think it is an illusion.

But I never could figure out the ones that said it was going WSW or even stalled.

So last year I didn't come and get my WUNDER humor and giant doses of real knowledge cause well we had it pretty easy so Hey again everyone! You do have to know I was watching a show on one of the Discovery Channels and they were showing Porch Light's efforts in Haiti and I was so proud of what you guys have done! 10, 000 cheers!So I'm back checking in after seeing the most insane right turn Clyde forecast map on our good buddy Earl cause that looked pretty ridunkulas for a storm to do something that precise that far out on the path so I'll be hanging here watching what my true know it alls have to say. Already warned the family in NC and Virgina to get their bottoms on in here to know what is going on.Hugs and Love and thanks for being here anytime we need a shelter in the storms for real knowledge :-)

Yes Sir you are!!!! You provided valuable information for me and my family when Rita, Humberto, Edourdo, and Ike came knocking on my door...your always there when someone has a question not just every 6 hours like the NHC...I stand and applaud your expertise...

Quoting CJ5:Landfall is going to be a race. Where Earl meets the trough is where the western movement will end and a N movement will begin. Now, how fast it moves NE will also be a question. There is a lot inhabited coast line we are looking at. Sad.

Assuming the High from Hell is not still in the way-and the Trough is strong enough and far enough south etc.

Our local weather stations are calling for an OBX landfall, and the center being around 75 miles off the VA coast, with rain and strong winds extending as far as Richmond, although richmond may only see 30-40 mph winds but some rain as well.

so i guess little towns like reedville and kilmarnock which are on the coast are gonna get nailed